mineoro fg/90

[abdou2014]

I do not have the values of the components of the diagram, I use another receiver

[Geo]

is the ferrite antenna in the frame a stimulator ???

I don't think.
But... only Esteban knows it, if he still remember it.

[abdou2014]

Thank you Geo , there is something weird, I feed both receiver and beep circuits with a 9v battery and 5v regulator,
As the battery works too much and the voltage decreases, I can calibrate my receiver in a very sensitive position 2.5 meters for a 1.5v wire, and when the battery is recharging it cannot be in this position.

[abdou2014]

I noticed when the beep gives sound, the receiver led goes out, it's like a ballance , and if each circuit has its own battery, I will not have this results

[Geo]

Thank you Geo , there is something weird, I feed both receiver and beep circuits with a 9v battery and 5v regulator,
As the battery works too much and the voltage decreases, I can calibrate my receiver in a very sensitive position 2.5 meters for a 1.5v wire, and when the battery is recharging it cannot be in this position.

I can't answer without see the schematic of receiver....

[humhum]

I don't think.
But... only Esteban knows it, if he still remember it.

16 Khz , OSC .

[abdou2014]

I can't answer without see the schematic of receiver....

It's Sony M-450 Microcassette Recorder with preamp and tranfo + beep generator

[Geo]

This has nothing to do with Mineoro MF receiver .

[abdou2014]

what's the difference, what's special about the mineoro receiver ???

[Geo]

Maybe nothing special... but it is n't a tape recorder.
Preamplifiers of tape recorders have filters so to work according to the NAB curve.
We need a flat curve.

[abdou2014]

Thanks , i need these values

[abdou2014]

Does the frequency of the oscillator and the coil increase or decrease near the phenomenon?
or there is a change in the amplitude ?

[abdou2014]

I have new after several tests and this time with the original mineoro oscillator

I hope to have help and answers from members who have knowledge of this receiver

there are two different results on two different frequency ranges

for LF frequencies, the reaction distance of a 1.5 v spark is 80 cm, and it also reacts to non-ferrous metals, a piece of aluminum 30x30cm from 35cm

for VLF frequencies, it reacts to a 1.5v spark at a distance of 3 meters, and it does not react to non-ferrous metals

please, what is the favorable result to detect the phenomenon, when it detects non-ferrous metals and the spark or when it only detects the spark at a great distance ???

[Geo]

I don't know the answer but i can tell you the follow.
1. Battery spark don't mean anything about the ability of a lrl.
2. Battery spark sheems that a lrl work better or worst if the lrl has n't differences at frequency or at working principle.

I believe it is clear

[brasilpb]

Maybe nothing special... but it is n't a tape recorder.
Preamplifiers of tape recorders have filters so to work according to the NAB curve.
We need a flat curve.

The mineoro LRL receivers, like the two box detectors, are super regenerative receivers, and the frequency response is not flat. If the input oscillating LC circuit is tuned to 40khz for example, it will have its maximum sensitivity for frequency between 35 to 45khz. Pre-amps for tape deck, they are well-designed circuits with high gain and low noise, but they have a wide passband, reproducing from a few hz to about 20khz, and this is not good because there would be a lot of interference from the electrical network and its harmonics . The phenomenon apparently occupies a large spectrum of frequencies, and the secret is to choose an interference-free frequency, and design a sensitive receiver for that band with a narrow passband. If the receiver has a flat response, it will be immune to a lot of interference, being forced to reduce the circuit gain to not give false signals.